The invention primarily concerns a plug and socket device in accordance with the independent claim.
Interfaces for connecting measuring devices have been known for a long time. DE 196 06 505 A1 discloses e.g. a plug for coupling to a diagnostic connection box. The diagnostic connection box contains socket-like electrical contact members in an insulating body, which are connected to devices to be tested. The plug has several plug pins cooperating with contact members of the connection box, which are connected to the electrical measuring devices. The plug has an inner lower housing containing a number of second socket-like electrical contact members, which are connected to the electrical measuring devices. The plug pins are disposed in a module and are extended on the side opposite to the side cooperating with the connection box to engage in the second socket-like electrical contact members of the lower housing. Finally, means are provided to detachably fix the module at the corresponding end of the plug.
DE 295 11 592 U1 discloses a diagnostic device for SCSI interfaces to display the signals of all relevant lines. Through monitoring of the relevant signal lines and evaluation of the corresponding signals, the signals are displayed in real time, and to facilitate recognition of very fast signals, these are additionally stored and displayed. Different available adaptors make this device suitable for almost all computers using an SCSI interface.
DE 198 53 511 A1 discloses a method for status-oriented maintenance of power switches using a measuring and processing computer, which is connected, via a diagnostic plug, to the control of the power switch to be tested. The measuring and processing computer has interfaces for measuring means which are mounted to the power switch for testing purposes and is connected to a computer comprising a data storage and input and output devices. Archived status data of the power switch to be examined and a maintenance program are loaded by the computer into the measuring and processing computer. The measuring and processing computer controls and monitors the processing of the predetermined maintenance program and receives manually entered data, measured values of the measuring means and signals of the control supplied through the diagnostic plug. The measuring and processing computer furthermore makes evaluations through comparison with the loaded archived status data and supplies the measured values, and/or values derived therefrom by an evaluation routine, to the computer. They are stored as maintenance protocol and are archived as new status data, wherein the maintenance program is processed interactively through dialogue with the user on the input and output devices and the user obtains information about activities to be carried out and input requests.
DE 42 29 566 C2 discloses a method and a device for automatic recognition of a device in the form of an intermediate device, end device or the like connected via a plug-socket arrangement to a supply device. A data transmission device transmits device-specific data, which is stored on the plug and/or on the socket, to an evaluation unit via a data transmission device disposed on the plug and on the socket. The evaluation unit compares the received data with stored data to recognize the connection device, wherein the device-specific data is transmitted between the data transmission devices disposed on the plug and socket in a contact-free fashion.
International committees (ITU, ETSI) and telecommunication administrations have proposed various switchable testing and examination circuits for digital communication systems having digital connections up to the consumer devices which permit localization of defects in the telecommunications system. Generally, such systems can determine whether or not the defect is within or outside of the central switching system but not whether or not the customer connection cables or customer devices are defective. WO 97/25806 discloses a method and network termination device for the localization of defects using switchable test circuits in a digital communications for speech and data, wherein the test circuit is connected to the output of the network termination device. The network termination device has a detector, a controllable switch and a network-terminating resistor for detecting control signals issued by the central switching system. In the event of malfunction, the central switching system generates the testing command and measurement sequence in dependence on the test procedure chosen in order to determine whether or not the portion of the network extending to the customer is defective. In order to prevent manipulation, the network termination device is filled with a solid mould mass so that only the outside contacts are accessible.
U.S. Pat. No. 4,626,633A discloses a tester for a customer connection cable, which is introduced between the customer connection cable and customer device. A manually operated switch can introduce a light diode between the a and b lines of the customer connection cable to indicate the presence of and/or polarity of the signal and calling voltages.
The above discussion of prior art acknowledges conventional plug devices for measuring and diagnostic purposes, in defect locating devices for telecommunications disposed in the central switching system and in current/voltage testers which can be introduced into a customer connection cable. The essential disadvantage of the above-described plug devices is that the devices only produce a mechanical and electrical connection. For diagnostic purposes, an additional socket must be provided for connecting the corresponding diagnostic device. Such switchable test circuits in digital communication systems often allow the central switching system to determine whether or not the communication segment leading to the customer is defective. However problems thereby often occur, since the customer interface is not free of feedback and since switching elements are necessarily introduced between the circuit switch and the user terminals. As a result thereof a customer defect can block command communication or the diagnostics may indicate no defect despite the fact that a defect is present at the users terminals which is actually caused by the network termination device. Moreover a manually operated tester introduced into the customer connection cable only permits limited-function, on-site testing of the customer connection cable.
In contrast to the known plug devices, it is the underlying purpose of the present invention to design the device such that, upon connection, diagnosis occurs automatically.